The purpose of this research proposal is to obtain a better understanding of receptor mechanisms mediating the hormonal and neurogenic control of cerebral blood flow, vascular permeability, and cerebrospinal fluid (CSF) secretion. This will be accomplished through the biochemical and pharmacological characterization of plasma hormone receptors located on the large extraparenchymal cerebral arteries, on the small intraparenchymal resistance vessels of the brain, and on the cellular elements of the choroid plexus. Techniques involved will include labeled ligand binding, measurement of hormone-sensitive adenylate cyclases, cell separation and isolation, immunocytochemistry, and measurement of cellular ion permeability. The results of this research will have relevance to such clinical neurological conditions as stroke, subarachnoid hemorrhage, hydrocephalus and migraine headache.